instruction:
You are given a sentence and a question. You're expected to write the correct answer based on the sentence.
question:
Sentence: Billy and Cody are walking together.  Cody gets tired and sits on a park bench. Question: When they leave the park together, who has walked farther?
answer:
Billy


question:
Sentence: Rolling a golf ball along the fairly is very easy, but rolling one along tall grass is difficult. Question: Which surface will let a golf ball roll for a longer distance?
answer:
fairway


question:
Sentence: A shopping cart rolls by itself across a parking lot. Then it gets to a field. The cart rolls only a little more after it enters the field. Question: Why does this happen?
answer:

the field is a rougher surface


